For distillative separation stacked packings are used in addition to walls and filler bodies. These packings are made in many different shapes. Packings of a cross-channel structure are particularly widespread.
Packings for a distillation column are normally formed of parts of identical geometry, for example zigzag-shaped bent sheet metal, expanded metal, or wire meshes. The purpose of this uniform geometric shape is to ensure that the flow of gas and liquid is uniform over the entire flow cross section of the column. Deviations, special surface effects of the fluid or streaming of the fluid must be avoided as these have a negative effect on the separation capacity. In order to avoid such negative irregularities on must provide every several meters liquid collectors and redistributors. In addition to the cost of this equipment, its height of from 1.5 to 2.5 m is disadvantageous, as it increases the overall column height.